dsh-ext-vision-proxy: Connecting the DeepSeek Harness text model to an external vision API

`dsh-ext-vision-proxy` is an external visual proxy plugin for DeepSeek Harness (DSH), maintained by jin123-alpha and licensed under the MIT license. Its core functionality is to enable text-only models such as DeepSeek-V3 and R1 to understand and analyze images, screenshots, and charts by connecting to an OpenAI-compatible visual API. The plugin mainly provides the `vision_describe` tool for model invocation, adds a status toggle and model selector to the chat input bar, and provides Base URL and API Key configuration, as well as connectivity testing features, on the settings page. It supports parsing multiple image formats and distinguishes between the session states of multimodal and text models. Installation requires executing `npm install` and `b`